Yes, they (Primedice) always make an announcement in their facebook pages if they are held giveaways. Currently if i not mistaken, there are 2 giveaways, first was 0.001 btc as giveaway and second is 0.01 btc (Randomly to 100 users) for share and like their video, although you still to meet 0.5 btc wagered and 100 chats in your account.
But when HH begins, they are always announce it on here, you can't find on facebook